There are image forming apparatuses that form images by color toner. The image forming apparatuses irradiate photoconductive drums with light scanning beams. The image forming apparatuses form electrostatic latent images on the photoconductive drums. The image forming apparatuses develop the electrostatic latent images to form toner images.
For example, an image forming apparatus includes a plurality of photoconductive drums. The image forming apparatus irradiates each of the photoconductive drums with a light scanning beam. It is necessary to accurately position relative positions of the toner images on the photoconductive drums between the photoconductive drums. In particular, if the scanning lines of the light scanning beams are bent, image quality deteriorates.
The bending of the scanning lines of the light scanning beams occurs due to various component errors and arrangement errors in scanning optical systems. In particular, in full-color image forming apparatuses, light scanning beams are folded using a plurality of reflection mirrors. Therefore, if the reflection surface of each reflection mirror is curved due to a processing error, the bending of the scanning lines increases.
In the related art, to correct the bending of the scanning lines, curving amounts of reflection mirrors are adjusted in some cases. For example, the rear surfaces of the reflection mirrors are pressed by retractable mechanisms such as screws.
However, in such adjustment methods, the reflection mirrors are curved only in one direction. Further, at the time of the adjustment, a stopper is necessary so that the reflection mirrors do not exceed deformation limits. Furthermore, since the retractable mechanisms are operated from the rear surfaces of the reflection mirrors toward the mirrors, operability is poor.